Bacterial HtpG/Hsp90 is a constitutive homodimer with an N-terminal ATPase domain, a middle domain, and a C-terminal dimerization domain; it undergoes an ATP-driven conformational cycle and collaborates with the Hsp70/DnaK system in client remodeling and refolding, lacking the dedicated cochaperone network of eukaryotic Hsp90.
"Bacterial HtpG is a constitutive homodimer dimerized via its C-terminal domain with three conserved domains per protomer (NTD, MD, CTD); it functionally collaborates with Hsp70 (DnaK) rather than a dedicated eukaryotic-type cochaperone network."